Combined luminous ophthalmoscope and retinoscope



Sept. 2,1930. c. H, KEELER 1 4 8 v COMBINED LUMINOUS OPHTHALMOSCOPE ANP- RETINOSCOPE Filed June 1, 1927 a retinoscope.

Patented Sept. I 2, l930 v oineinrins HENRY KEELEEE, oeis' mwmn Eire Latin commas Luminous m a osqemasshmmoscom i Application filedlune l, 192?, Serial No. 195,6 14,fand in Great Britain .Tuly 8,19%. P

The present invention relates to an instru{ ment for facilitating the examination. of the I eye, of the type in whichla beam of light from a suitable source is reflected into the 5 eye from a mirror ha ving a small aperture through which the desiredobservationinay be made, the chief object of the-invention :being to enablea'single instrument to be employed either as an ophthalmoscope or The invention consists in an instrument of the type set forth in which the beamof light ispassed through a system of lenseswhich may be varied so that the beam finally proj ected into the eye is either divergent, parallel' 0r convergent. The desired variation may be producedeither by the provision of lenses which may be readily inserted into or withdrawn from the pathof the beam or by making one or more of the lenses adjustable in the direction of the beam. In order that the invention may be clearly understood and readily carried into efiect it will now be described more fully, by way of example, by reference to the accompanying drawing, which illustrates a form of the instrument in which a combination of the methods of varying the lens system above referred to is employed, and in which Figures 1 and 2 are respectively front and side elevations,

Figures 3 and 4 are sections depicting diiferent adjustments of the lens system, and.

Figures 5 and 6 illustrate a detail to an enlarged scale.

In general formthe instrument is of known type in which a source'of light, such as an .4, being also provided. The whole is conveniently mounted on a cylindrical or like handle 6, which may serve to contain a dry battery to supply the lamp, or,-in the case in which itis desired to connect the lamp may be brought into line with the aperture.

to themains, a resistancei for cutting down the supply voltage"to a suitable, value. i v The light from the lamp lis passedthrough a system oflens es 'fitte'd inortothe tube 2, I

of these lenses being, if desired," built up ofv two or: more simple. lenses. #Theilens a-slid'e 8, whereby it; may be projected on to "7 situated nearest to;the lamp l fisjfitted in the axis ofthe tube 2 or withdrawnthere is withdrawn-the light-is notobscuredn. A

second lens .9 is carried'by a. short length of H tube 2, the motion being. limited bymeans tube,;10 mountedso as to slide within the i of pins projecting through slots 11 and se curing screws. 12 being provided, if desired.

A'thirdIlens-13 is carried inasocket pivoted; I

n14 so'thatit may-beplaced coaxially with P the tube 2or withdrawnfromthezpath of the beam of light to the; -position indicated in Figure l. V As indicated in Figure 3 all of the lenses 7,9 and lg may be employed, the lens 9 being placedas n'ear as" possible to the lamp. 1 or.

the, beam projected from the mirror will intermediately,'- as shown, and in that case v .bejdivergent, making the instrument suit-' able for useas anophthalmoscope. If the lens 9 bemaintained inthe same. position but the lenses/7. and 13 be withdrawn the projected beam will be either parallel or very slightlydivergent', such as .is required for use in retinoscopy; If it be desired to examine the eye at a'distance, say of-one metre, the arrangement indicated in Figurev 4 may be adopted, that is to; say, the. lenses 7 and 13 bein'g withdrawn, the .lens ;is moved as far away from the lamp 1 as pos sible and the, projected beam will then be slightly convergent, being brought to a focus approximately one metre from the mirror 3'. Iffa strongly convergent beam be re-,

-quired,- such as, "for example, for the purpose of examining the'cornea or the anterior chamber, the lens 9 would be adjusted to its position nearest to the lamp 1 or to any intermediate position and the lens 13 introduced into the beam.v Under these conditions the light is brought to-a focus at a com-.

paratively short distance, for example, three I v centimetres from the mirror 8. It will be obvious that with'the various combinations and arrangements of lenses which are posp sible a large variation in the concentration or I diffusion of thebeam can be obtalned.

As shown in Figures 5 and 6, provision maybe made for'introdulclng lnto the slide 8' a gratlcule or other transparency whereby 10 j a correspondin image may be thrown on the retina or any other desired portion of the eye. For thispurpose the slide 8 maybe fitted with a secondary slide having apertures or' sockets 16 andl? adapted respectively to 15 registerwith the lens 7 and with the aperture in the slide 8, the graticule 18 or the like being fixed in either of the apertures or sockets 16, 17 Alternatively, the secondary Y slide lfimay be of such a length as to extend over a'portion only ofthe slide- 8 sufficient to enable the, graticule or the like to register either with the aperture in the slide 8 or with the lens 7 the aperture 16 being then unnecessary.f Further, it will be obvious that any other suitably'mounted object may be similarly placed in the apertureor socket 16. or 17 or mounted in a separatesecondary slide to be substituted for that shown and an enlarged image thereof thereby projected either I on to or into the eye or on toja suitable screen placed in the path of the beam projected from the mirror 3. c 5 7 What I claim and desire to secureby Letterse Patent of the United States is 1. An instrument for the production of a beam of light of Varying characteristics, comprising in combination a source of light, a series oflenses'so disposed that a'beam of light from said s'ource'passes through them 40 seriatim, a reflecting surface inclined to the axis of-said lenses, means for adjusting the position of one of said lenses in the direction of said axis, a graticule, and means whereby said graticule may be projected into or withdrawn from said beam of light.

2. An instrument for the production of a beam of lightof varying characteristics comprising-in combination a source of light, a series of lenses --so disposed that abeam of .50 light from said source passes through them seriatim ,.a-refiecting surface inclined to the axis of said lenses, a slide formed with an aperture and supporting at least one of said j lenses and means whereby said slide may be I moved in'orderto bring either said'aperture I a or said lenses supported by said slide into the 1 path of said beam of light, a secondary slide mounted in saidcfirst mentioned slide and a graticule' mounted in said secondary slide.

CHARLES HENRY KEELER. 

